8 research outputs found
Recovering the real-space correlation function from photometric redshift surveys
Measurements of clustering in large-scale imaging surveys that make use of
photometric redshifts depend on the uncertainties in the redshift
determination. We have used light-cone simulations to show how the deprojection
method successfully recovers the real space correlation function when applied
to mock photometric redshift surveys. We study how the errors in the redshift
determination affect the quality of the recovered two-point correlation
function. Considering the expected errors associated to the planned photometric
redshift surveys, we conclude that this method provides information on the
clustering of matter useful for the estimation of cosmological parameters that
depend on the large scale distribution of galaxies.Comment: 11 pages, 8 figures. Accepted for publication in MNRA
The Power Spectrum of Clusters of Galaxies and the Press-Schechter Approximation
We examine the power spectrum of clusters in the Press-Schechter (PS) theory
and in N-body simulations to see how the power spectrum of clusters is related
to the power spectrum of matter density fluctuations in the Universe. An
analytic model for the power spectrum of clusters for their given number
density is presented, both for real space and redshift space. We test this
model against results from N-body simulations and find that the agreement
between the analytic theory and the numerical results is good for wavelengths
Mpc. On smaller scales non-linear processes that are not
considered in the linear PS approximation influence the result. We also use our
analytic model to study the redshift-space power spectrum of clusters in cold
dark matter models with a cosmological constant (CDM) and with a
scale-invariant Harrison-Zel'dovich initial spectrum of density fluctuations.
We find that power spectra of clusters in these models are not consistent with
the observed power spectra of the APM and Abell-ACO clusters. One possible
explanation for the observed power spectra of clusters is an inflationary
scenario with a scalar field with the potential that has a localized steplike
feature. We use the PS theory to examine the power spectrum of clusters in this
model.Comment: 16 pages, 5 figures. Accepted by Ap